It's hard to tell whether or not the claims are credible or not as he links to no sources for any of the figures. Given the article's author I'd want to validate any such claims.
Besides, it is the web, it is only courtesy to the reader link and cite. I think less of mainstream media who don't link to source or cherry pick. So I am certainly going to think less of someone who claims to be a scientist who doesn't bother, and question their motives just as strongly.